A system for managing home security has been proposed. In such a system, a sensor that can detect a locking state such as a direction of a key is installed on a front door and windows of a home, thereby monitoring the locking state of the front door and the windows.
For example, it is conceivable that, when a resident approaches a front door or a window, a sensor transmits information of a locking state to a mobile terminal such as a mobile phone held by the resident by near field communication such as Bluetooth®, and the mobile terminal memorizes the information to manage the security.
However, the resident may change the locking state of the front door and windows without holding the mobile terminal.
Therefore, for example, it is conceivable to alert the sensor that does not notify any information for a certain period of time or more by the mobile terminal.
However, in this case, even if there is no change in the locking state, an unnecessary alert may be generated in the mobile terminal.